Certain conventional snacks consist of baked dough material and a filling wherein the snack is usually prepared by co-extrusion of bread crumbs and the filling. However, these snacks have an irregular shape, and problems occur during baking when the filling content exceeds 40 wt. %.
Snacks having a regular shape can be obtained using a moulding process to give products with exposed fillings. In particular, EP 1 256 280 B9, assigned to Kraft Foods, describes a process for making bread snacks with a filling wherein the filling has a high water content. Such snacks have shelf-lives at chilled or ambient temperatures of more than 6 weeks. The process described therein is characterized in that ground baked bread is used as raw material. The process is said to be particularly useful for snacks on the basis of rye bread and includes the following steps:                (i) the baked bread is ground,        (ii) water is added to the ground bread to improve its extrudability and to adjust its water activity to about 0.95-0.98 or higher,        (iii) the bread-water mixture is kneaded to a bread dough,        (iv) the bread dough is coextruded with the filling and        (v) snacks are formed, packed and pasteurized.        
The water activity (aw) of a substance is defined as the percent equilibrium relative humidity (% ERH) divided by 100. It can also be defined as the ratio of the water vapour pressure over the substance (p) to that over pure water (p0):aw=p/p0 
Multiplication of the water activity by 100 gives the relative humidity of the atmosphere in equilibrium with the food:ERH(%)=100×aw 
In practice, the water activity is a measure of “free” water in a food sample as opposed to “bound” water. Water activity merits closer attention as it is a critical factor that determines the shelf life of food products. While temperature, pH and several other factors can influence whether an organism will grow in a food and the rate at which it will grow, water activity may be regarded as the most important factor. Most bacteria do not grow at water activities below 0.91, and most moulds cease to grow at water activities below 0.80. By measuring the water activity of foodstuffs, it is possible to predict which microorganisms will or will not be potential sources of spoilage.
US 2006/0110514 A1, assigned to Kraft Foods, on the other hand, discloses shaped snacks made from baked dough crumbs. In particular, this reference describes a process for shaped snacks comprising the steps of shredding baked dough material, forming the shredded baked dough material to produce a shell, and introducing the filling into the shell.
None of the prior art snacks endures heat treatment after assembly, which would result in beneficial taste and appearance. Since consumers are interested in snacks that are appealing and shelf-stable without preservatives and, at the same time, have a high filling content wherein the filling is fully encased with crumb material, there was the need to develop new processes for the preparation of such snacks.
In view of the knowledge about the prior art snacks, the present inventors have created a process for the preparation of an appealing snack comprising a crumb material casing and a filling wherein the encased snack has an evenly shaped surface, a long shelf-life, and does not need preservatives.